Added circleci config file

Author: gregchamberlain

circle.yml

@@ -0,0 +1,13 @@
+machine:
+  environment:
+    PATH: "${PATH}:${HOME}/${CIRCLE_PROJECT_REPONAME}/node_modules/.bin"
+
+dependencies:
+  override:
+    - yarn
+  cache_directories:
+    - ~/.cache/yarn
+
+test:
+  override:
+    - yarn test